Utjecaj klorida na korozijsku postojanost nehrđajućih čelika u vodi

master's thesis

• Title (english): Influence of chlorides on corrosion resistance of stainless steels in water
• Author: Krešimir Mandić
• Mentor: Vinko Šimunović (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2018-12-06, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Production Mechanical Engineering

Abstract

Korozijski postojani čelici imaju iz dana u dan sve veću primjenu u suvremenoj proizvodnji, jer se područje njihove uporabe sve više proširuje.Koriste se sve više i u građevinarstvu, nautici, brodogradnji, itd. Predstavljaju jednu od najvažnijih skupina konstrukcijskih postojanih materijala. Istodobno ovi konstrukcijski materijali u određenim uvjetima postaju vrlo skloni posebno lokalnim korozijskim oštećenjima. U teorijskom dijelu prikazana je podjela nehrđajućih čelika. Također je opisana korozijska postojanost nehrđajućih čelika te čimbenici koji utječu na korozijsku postojanost. Opisani su svi mehanizmi korozije, a posebno je obrađena problematika nastanka rupičaste korozije, te utjecaj vanjskih faktora na mehanizam rupičaste korozije. Poseban naglasak je dan na utjecaj promjene udjela klorida u vodenim otopinama na pojavu rupičaste korozije. U eksperimentalnom dijelu rada provedena su elektrokemijska korozijska ispitivanja utjecaja klorida na korozijsku postojanost nehrđajućih čelika. U ispitivanjima su korišteni austenitni nehrđajući čelici AISI 321, AISI 316L i UNS S31050, te duplex čelik AISI 2304 i superduplex nehrđajući čelik AISI 2507 koji su ispitivani u vodama sa različitim udjelima klorida (50 ppm Cl - , 1900 ppm Cl - te19000 ppm Cl - ) te su određeni elektrokemijski korozijski parametri. Nakon eksperimentalnog dijela analizirani su rezultati, te je na temelju rezultata izveden zaključak.

Abstract (english)

Corrosion resistant steels have been increasingly used in modern manufacturing day by day, as their use area is increasingly expanding. They are increasingly used in construction, nautical, shipbuilding, etc. They represent one of the most important groups of structure corrosion resistant materials. At the same time these materials become very prone to local corrosion damage in certain conditions. The theoretical part shows the various types of stainless steels. The corrosion resistance of stainless steel and the factors that influence corrosion resistance are also described as well as corrosionmechanisms. Special emphasis was given on the problems of the pitting corrosion, as well as the influence of external factors on the perforation corrosion mechanism. Particular emphasis was given to the effect of changing the chloride content in aqueous solutions on occurrence of pitting corrosion. In the experimental part, electrochemical corrosion tests have been carried out on chloride corrosion on the corrosion resistance of stainless steels. Austenitic stainless steels AISI 321 and AISI 316L, supeaustenitic stainless steel UNS S31050, duplex stainless steel AISI 2304 and superduplex stainless steel AISI 2507 steel were tested in in waters with different chloride contents (50 ppm CI - , 1900 ppm CI - and 19000 ppm CI - )and electrochemical corrosion parameters were defined. After the experimental part, the results were analyzed and based on the results the conclusion was drawn.

• Keywords: nehrđajući čelici; rupičasta korozija; kloridi
• Keywords (english): stainless steels; pitting corrosion; chlorides
• Language: croatian
• URN:NBN: urn:nbn:hr:235:744866
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 23:29:13